|Year : 2015 | Volume
| Issue : 3 | Page : 456-458
Inducible clindamycin resistance among staphylococcus aureus isolates in a tertiary care hospital of Assam
C Phukan1, GU Ahmed2, PP Sarma1
1 Department of Microbiology, Gauhati Medical College and Hospital, Guwahati, Assam, India
2 Department of Biotechnology, Gauhati University, Guwahati, Assam, India
|Date of Submission||22-Jan-2014|
|Date of Acceptance||13-Nov-2014|
|Date of Web Publication||12-Jun-2015|
Department of Microbiology, Gauhati Medical College and Hospital, Guwahati, Assam
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Phukan C, Ahmed G U, Sarma P P. Inducible clindamycin resistance among staphylococcus aureus isolates in a tertiary care hospital of Assam. Indian J Med Microbiol 2015;33:456-8
|How to cite this URL:|
Phukan C, Ahmed G U, Sarma P P. Inducible clindamycin resistance among staphylococcus aureus isolates in a tertiary care hospital of Assam. Indian J Med Microbiol [serial online] 2015 [cited 2019 Nov 22];33:456-8. Available from: http://www.ijmm.org/text.asp?2015/33/3/456/158603
Staphylococcus aureus is one of the most common causes of nosocomial infections throughout the world and the epidemiology is rapidly changing worldwide. , (Speller DC, et al., 1997) Clindamycin has been an option for treating both Methicillin-sensitive Staphylococcus Aureus (MSSA) and Methicillin-Resistant Staphylococcus Aureus (MRSA) infections because it can be given orally as it has excellent tissue penetration and no dosage adjustments are required in the presence of renal disease and in penicillin-allergic patients.  (Fiebelkorn KR, et al., 2003) The aim of our study was to incorporate the double-disk diffusion test (D test) which is a simple and reliable method to the routine antibiotic susceptibility test to guide the clinicians and prevent misuse of antibiotics.
A total of 215 Staphylooccus aureus isolates were screened from various clinical samples in the hospital of which 160 (74.42%) were MRSA and 55 (25.58%) were MSSA. Among the Staphylococcus aureus isolates, 71% were susceptible to erythromycin and clindamycin, 13% were resistant to erythromycin as well as clindamycin and as a whole 29% were resistant to erythromycin. The discordance between erythomycin and clindamycin were 16% among the isolates while discordance between MRSA and MSSA was 29.37% and 23.63%, respectively. The susceptibility of erythomycin and clindamycin among the isolates of Staphylooccus aureus were found to be 67.2% among MRSA and 32.8% among MSSA and belonged to sensitive phenotype.
The overall prevalence of inducible clindamycin resistance (MLSBi) among the Staphylococcus aureus isolates as confirmed by the D-test was 15 (7%) , with 12 (7.5%) of MRSA and 3 (5.5%) of MSSA. The MS phenotype was found to be higher in MSSA as compared to MRSA (12.7% vs 6.3%). The constitutive MLSB phenotype among the isolates was found to be 16.9% in MRSA and 3.6% MSSA [Table 1] and [Figure 1]. Thus, both the constitutive and inducible resistance phenotypes were found to be significantly higher in MRSA isolates as compared to MSSA (P < 0.03 and P < 0.02, respectively by Chi-square test). We found that clindamycin is a suitable alternative drug in staphylococcal infections because of the lower level of inducible clindamycin resistance and vancomycin or linezolid should not be used routinely among the MRSA isolates.
|Figure 1: CLI induction testing of S. aureus by disk diffusion. E: ERY disk (15 μg); CD: CLI disk (2 μg). MS Phenotype (a), Constitutive MLSB Phenotype (b), S phenotype (c)|
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